The present invention relates to mechanism for inflating and deflating pneumatic tires on a moving or stationary vehicle. The ability to inflate and deflate tires is extremely useful for mating the tire traction with the terrain and for obtaining best features of tire wear and vehicle riding quality. When greater traction is needed (for example in snow or sand), the tires can be partially deflated to give more surface contact with the terrain. When less traction is needed (such as on a paved highway), the tire is inflated, reducing rolling resistance.
The inflation/deflation feature is also useful when the vehicle payload weight varies. When the vehicle payload is increased, greater total force is exerted on the tires. The greater force increases the surface area of the tire in contact with the terrain. To balance this force, the tire pressure should be increased to keep traction and rolling resistane at their optimum. When the payload weight is reduced, the total force exerted on the tires is decreased. The tire pressure should be reduced for traction, riding quality, and rolling resistance to remain at an optimum.
There are in existence some patented devices designed for tire inflation/deflation purposes. Examples of such devices are shown in U.S. Pat. No. 1,855,101 to R. Daneel, U.S. Pat. No. 2,579,048 to W. Paul, U.S. Pat. No. 2,944,579 to W. Kamm et al, U.S. Pat. No. 4,431,043 to F. Goodell et al, and U.S. Pat. No. 4,434,833 to G. Swanson, et al.
The present invention is directed to a tire inflation/deflation system for a military (or civilian) vehicle wherein:
1. The tire pressure can be controlled at any selected value within the pressure range of the system.
2. The tire pressure can be changed while the vehicle is either moving or stationary.
3. Each tire has an individual sealing mechanism associated therewith, whereby loss of pressure in one tire does not affect the pressure in the remaining tires.
4. Inflation/deflation air lines used in the system are depressurized while the vehicle is in its normal run mode, whereby leak damage or breakage of lines will not cause loss of air reserve or tire pressures.
5. Tire pressurization/depressurization operations can be performed in a comparatively short period of time without leaving the vehicles armor protection or stopping as may be necessary to quickly convert the vehicle from a soft-soil operating mode to a paved highway mode, or vice versa.
6. The system can be incorporated into existing vehicles with minimum modification of the vehicle structure.
7. The system is manufacturable and installable on the vehicle at a relatively small cost.